add test for two exclusive databases for one service

src/test/kotlin/com/sortinghat/pattern_detector/domain/services/DatabasePerServiceDetectorTest.kt

@@ -28,4 +28,18 @@ internal class DatabasePerServiceDetectorTest {
         val results = underTest.getResults()
         assertEquals(1, results.size)
     }
+
+    @Test
+    fun `it correctly do not detect when service uses two databases`() {
+        // given
+        val visitable = Scenarios.oneServiceWithTwoDatabases()
+        visitable.forEach { it.accept(MetricCollector()) }
+
+        // when
+        visitable.forEach { it.accept(underTest) }
+
+        // then
+        val results = underTest.getResults()
+        assertEquals(0, results.size)
+    }
 }

src/test/kotlin/com/sortinghat/pattern_detector/domain/services/Scenarios.kt

@@ -22,5 +22,16 @@ class Scenarios {
 
             return listOf(service)
         }
+
+        fun oneServiceWithTwoDatabases(): List<Visitable> {
+            val service = Service(name = "foo", systemName = Slug.from("foo system"))
+            val db1 = Database(name = "db 1", DataSource.MongoDb)
+            val db2 = Database(name = "db 2", DataSource.PostgreSql)
+
+            DatabaseUsage(service, database = db1, accessMode = DatabaseAccessMode.ReadWrite)
+            DatabaseUsage(service, database = db2, accessMode = DatabaseAccessMode.ReadWrite)
+
+            return listOf(service)
+        }
     }
 }